The fatty acids present in the rumen of lambs fed on a flaked maize ration.

The cobalt-deficient diet introduced by Stewart (1947) contains flaked maize as t..is foodstuff contains very little cobalt. Experiments in which this ration was used have already been described (Phillipson & Mitchell, 1952), and examination of the rumen contents of some of the lambs involved revealed an unusual bacteriological picture (Masson, 1950, 1951), for the protozoa had disappeared from the rumen and the usual population of iodophilic cocci seen in sheep fed on diets containing starch had been largely displaced by rod-like sporulating organisms later identified as Cbstridium butyrzkum. In addition, lactic acid-producing bacteria (lactobacilli) were isolated. These observations were most marked in those lambs receiving cobalt, for they ate more of the flaked maize mixture. Lambs receiving no supplementary cobalt did not show this picture to such a marked extent. Masson’s observations suggested that the acids formed as a result of fermentation would not be present in their usual proportions, and for this reason chromatographic separation of the steam-volatile acids was undertaken and the results are presented in this paper.